function nextPage()
	{
		thisPage++;
		if(thisPage == 21) thisPage = 0;
		location = "gr2."+thisPage+".htm";	
	}
	
function prevPage()
	{
		if(thisPage>0)
			{
				thisPage = thisPage - 1;
				location = "gr2."+thisPage+".htm"
			}
	}